COLOR ESTIMATION 



71 



CONCENTRATION 



pink yellow greenish blue 



red olive-brown blue 



reddish orange greenish yellow purplish blue 

 reddish brown olive bluish purple 



orange-pink yellow-green purple 



orange olive-green reddish purple 



brown jellowish green purplish pink 



ycllowwh orange green red-purple 



yellowish brown bluish green purplish red 



blue-green 



For accurate measurement of color 

 employ Photoelectric Colorimeter or 

 Photoelectric Microphotometer. See 

 Hemoglobin Estimation. 

 Color Preservation in museum specimens. 

 Fix 24 hrs. or less in 10% formalin. 

 Wash in running water 3-6 hrs. Stand 

 in 2% aq. ammonia 5-10 min. which 

 hastens return of original colors. Run- 

 ning water another hour. Mount for 

 permanent exhibition in mixture made 

 as follows: Filter a sat. sol. antimony 

 trioxide in aq. dest. (about 5 gni. per 

 liter). To each 1000 cc. filtrate add 100 

 gm. potassium acetate, 100 gm. chloral 

 hydrate and 50 cc. glycerin. Stir until 

 completely dissolved (Meiller, F. H., 

 J. Tech. Methods, 1938, 18, 57-58). 



Mallory (p. 380) recommends for this 

 purpose the methods of I'Qiiserling and 

 Jores. 



There are 3 Kaiserling solutions : 



1. For fixation: Formalin, 40 cc; tap 

 water, 2000 cc; potassium nitrate, 30 

 gm. and potassium acetate, 60 gm. 

 Small specimens require 1-14 days. 

 Large ones can be more uniformly fixed 

 by vascular Perfusion. Sometimes it 

 is advisable to inject fixative into central 

 parts of the tissue with a hypodermic 

 syringe and long needle. Do not use 

 too much pressure and be careful not to 

 let any of the fixative spurt back into 

 one's face. Before the next step wash 

 in running water for about 12 hrs. 



2. For color restoration: Place the 

 tissue in 80% ethyl alcohol for 10-60 

 min. and watch for optimum coloration. 

 If left too long in the alcohol the colors 

 fade. Rinse in water and transfer to 

 No. 3. 



3. For final preservation: Change to 

 glycerin, 500 cc. ; 1% aq. arsenious acid, 

 200 cc ; tap water, 2300 cc ; potassium 

 acetate, 250 gms.; thymol, 2.5 gm. To 

 obviate difhculty of dissolving the 

 arsenious acid and to sterilize add 25 

 gms. arsenic trioxide to 2500 cc water 

 + the thymol crystals first ground up 

 in a mortar and place in steam sterilizer 

 for 6 hrs. Then add other substances. 



There are 2 Jores solutions. 



1. For fixation: Chloral hydrate, 50 

 gms.; artificial Carlsbad salts (sodium 

 sulfate, 22 gm.; sodium bicarbonate, 20 

 gm. ; sodium chloride, 18 gm. ; potassium 



nitrate, 38 gm.; potassium sulphate, 2 

 gm.), 50 gm.; formalin, 100 cc. ; tap 

 water, 1000 cc. Allow to act 2-14 days 

 depending on size, wash 12 hrs. in run- 

 ning water. 



2. For final preservation: Potassium 

 acetate, 300 gm., glycerin, 600 cc; aq. 

 dest., 1000 cc. 



Mallory suggests fixation in Jores' 

 first solution and preservation in Kaiser- 

 ling's third solution. 



Columbium, see Atomic Weights. 



Concentration. 1. Tubercle bacilli in spu- 

 tum. Nagy (A.H., J. Lab. & Clin. 

 Med., 1939, 25, 67-71) having critically 

 evaluated several techniques recom- 

 mends Pottenger's Dilution- Flotation 

 method. Shake equal parts sputum and 

 0.5% aq. sodium hydroxide for 10 min. 

 Digest in water bath at 56°C. for 30 

 min. Add 1 ml. (= 1 cc) hydrocarbon 

 (gasoline or xylene), then 200 ml. aq. 

 dest. and shake 10 min. Allow hydro- 

 carbon to collect at top 15-20 min. 

 Take up hydrocarbon layer in rubber 

 bulbed pipette. Keep in vertical posi- 

 tion until supernatant fluid separates 

 from hydrocarbon, 5-10 min. Make 

 smears from hydrocarbon and dry. 

 Remove hydrocarbon by washing with 

 ether. Stain with carbol fuchsin 3 hrs. 

 or longer. Decolorize with acid alco- 

 hol 30 sec or less. If further decolor- 

 ization is required employ 10% aq. 

 sodium sulphate. Counterstain with 1% 

 aq. picric acid or with methylene blue. 

 The concentration of bacilli is about 33 

 times. Perhaps a modification of the 

 method could be used for leprosy or- 

 ganisms in emulsions of tissues. See 

 al.so Pottenger, J. E., Am. Rec Tuberc, 

 1939, 40, 581. Concentration of tuber- 

 cle bacilli in spinal fluids (Hanks, J. H. 

 and Feldman, H. A., J. Lab. & Clin. 

 Med., 1939, 25, 886-892). It is often 

 necessary to concentrate for micro- 

 scopic study objects which are not 

 present in abundance and which might 

 otherwise be overlooked. See exami- 

 nation of Feces for ova of parasites, of 

 Urine for sediment. 



2. Leprosy bacilli for chemical analy- 

 sis. Ravold's method for leprosy bacilli 

 can perhaps be used for others. Rela- 

 tively large masses of bacilli -laden cells 

 are dissected away from neighboring 

 uninvolved tissue and from necrotic 

 tissue when present in the centers of 

 the nodules. They are placed in a 

 Wueller press without addition of any 

 fluid. On exertion of pressure many 

 of the cells are ruptured and the tissue 

 fluid, together with cytoplasm, nucleo- 

 plasm and some entire cells, passes 

 through minute holes in the press and is 

 collected, leaving most of the fibrous 



